talons

commit 427ba2698e8a780c61597357cbe05a37c0946cff
parent db434c2b05aec33ca6c3cc4fda792d40cf34942c
Author: Ricardo Mones <ricardo@mones.org>
Date:   Mon, 30 Jan 2017 23:22:20 +0100

Render SVG scaled to default icon size

Default icon sizes are parsed from icon data, which is suboptimal
since these sizes can be known at compile time.

Diffstat:
M
src/stock_pixmap.c
 | 
159
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-

1 file changed, 158 insertions(+), 1 deletion(-)
diff --git a/src/stock_pixmap.c b/src/stock_pixmap.c
@@ -494,6 +494,163 @@ GtkWidget *stock_pixmap_widget(StockPixmap icon)
 	return NULL;
 }
 
+#ifdef HAVE_SVG
+/*
+ * Renders a SVG into a Cairo context at the given dimensions keeping
+ * the aspect ratio.
+ *
+ * Adapted from https://developer.gnome.org/rsvg/2.40/RsvgHandle.html
+ * #rsvg-handle-set-size-callback
+ */
+void render_scaled_proportionally(RsvgHandle *handle, cairo_t *cr, int width, int height)
+{
+	RsvgDimensionData dimensions;
+	double x_factor, y_factor;
+	double scale_factor;
+
+	rsvg_handle_get_dimensions(handle, &dimensions);
+
+	x_factor = (double) width / dimensions.width;
+	y_factor = (double) height / dimensions.height;
+
+	scale_factor = MIN(x_factor, y_factor);
+
+	cairo_scale(cr, scale_factor, scale_factor);
+
+	rsvg_handle_render_cairo(handle, cr);
+}
+
+/*
+ * Generates a new Pixbuf from a Cairo context of the given dimensions.
+ *
+ * Adapted from https://gist.github.com/bert/985903
+ */
+GdkPixbuf *pixbuf_from_cairo(cairo_t *cr, gboolean alpha, int width, int height)
+{
+	gint p_stride, /* Pixbuf stride value */
+	     p_n_channels, /* RGB -> 3, RGBA -> 4 */
+	     s_stride; /* Surface stride value */
+	guchar *p_pixels, /* Pixbuf's pixel data */
+	       *s_pixels; /* Surface's pixel data */
+	cairo_surface_t *surface; /* Temporary image surface */
+	GdkPixbuf *pixbuf; /* Returned pixbuf */
+
+	/* Create pixbuf */
+	pixbuf = gdk_pixbuf_new
+			(GDK_COLORSPACE_RGB, alpha, 8, width, height);
+	if (pixbuf == NULL) {
+		g_warning("failed to create a new %d x %d pixbuf", width, height);
+		return NULL;
+	}
+	/* Obtain surface from where pixel values will be copied */
+	surface = cairo_get_target(cr);
+	if (cairo_surface_status(surface) != CAIRO_STATUS_SUCCESS) {
+		g_warning("invalid cairo surface for copying");
+		return NULL;
+	}
+	/* Inspect pixbuf */
+	g_object_get(G_OBJECT(pixbuf),
+		"rowstride", &p_stride,
+		"n-channels", &p_n_channels,
+		"pixels", &p_pixels,
+		NULL);
+	/* and surface */
+	s_stride = cairo_image_surface_get_stride(surface);
+	s_pixels = cairo_image_surface_get_data(surface);
+
+	/* Copy pixel data from surface to pixbuf */
+	while (height--) {
+		gint i;
+		guchar *p_iter = p_pixels, *s_iter = s_pixels;
+		for (i = 0; i < width; i++) {
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+			/* Pixbuf: RGB(A) - Surface: BGRA */
+			gdouble alpha_factor = (gdouble)0xff / s_iter[3];
+			p_iter[0] = (guchar)( s_iter[2] * alpha_factor + .5 );
+			p_iter[1] = (guchar)( s_iter[1] * alpha_factor + .5 );
+			p_iter[2] = (guchar)( s_iter[0] * alpha_factor + .5 );
+			if (p_n_channels == 4)
+				 p_iter[3] = s_iter[3];
+#elif G_BYTE_ORDER == G_BIG_ENDIAN
+			/* Pixbuf: RGB(A) - Surface: ARGB */
+			gdouble alpha_factor = (gdouble)0xff / s_iter[0];
+			p_iter[0] = (guchar)( s_iter[1] * alpha_factor + .5 );
+			p_iter[1] = (guchar)( s_iter[2] * alpha_factor + .5 );
+			p_iter[2] = (guchar)( s_iter[3] * alpha_factor + .5 );
+			if (p_n_channels == 4)
+				p_iter[3] = s_iter[0];
+#else /* PDP endianness */
+			/* Pixbuf: RGB(A) - Surface: RABG */
+			gdouble alpha_factor = (gdouble)0xff / s_iter[1];
+			p_iter[0] = (guchar)( s_iter[0] * alpha_factor + .5 );
+			p_iter[1] = (guchar)( s_iter[3] * alpha_factor + .5 );
+			p_iter[2] = (guchar)( s_iter[2] * alpha_factor + .5 );
+			if (p_n_channels == 4)
+				p_iter[3] = s_iter[1];
+#endif
+			s_iter += 4;
+			p_iter += p_n_channels;
+		}
+		s_pixels += s_stride;
+		p_pixels += p_stride;
+	}
+	/* Destroy context */
+	cairo_destroy(cr);
+
+	return pixbuf;
+}
+
+/*
+ * Renders a SVG file into a pixbuf with the dimensions of the
+ * given pixmap data (optionally with alpha channel).
+ */
+GdkPixbuf *pixbuf_from_svg_like_icon(char *filename, GError **error, StockPixmapData *icondata, gboolean alpha)
+{
+	int width, height;
+	cairo_surface_t *surface;
+	cairo_t *context;
+	RsvgHandle *handle;
+
+	cm_return_val_if_fail(filename != NULL, NULL);
+	cm_return_val_if_fail(icondata != NULL, NULL);
+
+	if (sscanf((icondata->data)[0], "%d %d ", &width, &height) != 2) {
+		g_warning("failed reading icondata width and height");
+		return NULL;
+	}
+
+	/* load SVG file */
+	handle = rsvg_handle_new_from_file(filename, error);
+	if (handle == NULL) {
+		g_warning("failed loading SVG '%s': %s (%d)", filename,
+				(*error)->message, (*error)->code);
+		return NULL;
+	}
+	/* create drawing context */
+	surface = cairo_image_surface_create(
+			alpha? CAIRO_FORMAT_ARGB32: CAIRO_FORMAT_RGB24,
+			width, height);
+	if (cairo_surface_status(surface) != CAIRO_STATUS_SUCCESS) {
+		g_warning("failed to create a cairo surface: %s",
+				cairo_status_to_string(cairo_surface_status(surface)));
+		g_object_unref(handle);
+		return NULL;
+	}
+	context = cairo_create(surface);
+	cairo_surface_destroy(surface);
+	if (cairo_status(context) != CAIRO_STATUS_SUCCESS) {
+		g_warning("failed to create a cairo context: %s",
+				cairo_status_to_string(cairo_status(context)));
+		cairo_destroy(context);
+		return NULL;
+	}
+	/* render SVG */
+	render_scaled_proportionally(handle, context, width, height);
+	/* build result and destroy context */
+	return pixbuf_from_cairo(context, alpha, width, height);
+}
+#endif
+
 /*!
  *\brief
  */
@@ -532,7 +689,7 @@ try_next_extension:
 					GError *err = NULL;
 #ifdef HAVE_SVG
 					if (!strncmp(extension[i], ".svg", 4)) {
-						pix = rsvg_pixbuf_from_file(icon_file_name, &err);
+						pix = pixbuf_from_svg_like_icon(icon_file_name, &err, pix_d, TRUE);
 					} else {
 						pix = gdk_pixbuf_new_from_file(icon_file_name, &err);
 					}